cp's OEIS Frontend

This is a front-end for the Online Encyclopedia of Integer Sequences, made by Christian Perfect. The idea is to provide OEIS entries in non-ancient HTML, and then to think about how they're presented visually. The source code is on GitHub.

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A331306 Lexicographically earliest infinite sequence such that a(i) = a(j) => A285732(i) = A285732(j) for all i, j.

Original entry on oeis.org

1, 2, 2, 3, 4, 5, 6, 5, 3, 7, 8, 9, 10, 9, 11, 12, 13, 7, 6, 14, 15, 16, 17, 14, 18, 13, 19, 20, 21, 22, 23, 11, 8, 23, 24, 25, 26, 27, 28, 19, 29, 17, 30, 31, 32, 33, 34, 35, 30, 15, 12, 28, 36, 37, 38, 39, 40, 41, 42, 24, 43, 22, 42, 44, 45, 46, 47, 48, 49, 50, 36, 20, 16, 35, 51, 52, 53, 54, 55, 56, 57, 58, 51, 31, 59, 27, 50, 60, 61, 62, 63, 64, 65, 66, 67, 68, 44, 25, 21, 41
Offset: 1

Views

Author

Antti Karttunen, Jan 19 2020

Keywords

Comments

Restricted growth sequence transform of A285732 (when considered as an one-dimensional sequence).
For all i, j:
a(i) = a(j) => A003989(i) = A003989(j),
a(i) = a(j) => A331307(i) = A331307(j) => A072030(i) = A072030(j).

Crossrefs

Programs

  • PARI
    up_to = 25425; \\ = binomial(225+1,2)
    rgs_transform(invec) = { my(om = Map(), outvec = vector(length(invec)), u=1); for(i=1, length(invec), if(mapisdefined(om,invec[i]), my(pp = mapget(om, invec[i])); outvec[i] = outvec[pp] , mapput(om,invec[i],i); outvec[i] = u; u++ )); outvec; };
    A000027pairton(a,b) = ((2+((a+b)^2 - a) - (3*b))/2);
    A285732sq(n, k) = if(n==k,-n,if(n>k,A000027pairton(n-k,k),A000027pairton(n,k-n)));
    A285732list(up_to) = { my(v = vector(up_to), i=0); for(a=1,oo, for(col=1,a, i++; if(i > up_to, return(v)); v[i] = A285732sq(col,(a-(col-1))))); (v); };
    v331306 = rgs_transform(A285732list(up_to));
    A331306(n) = v331306[n];

A331307 Lexicographically earliest infinite sequence such that for all i, j: a(i) = a(j) => f(i) = f(j), where f(n) = A285722(n), except f(1) = -1.

Original entry on oeis.org

1, 2, 2, 3, 4, 5, 6, 5, 3, 7, 8, 9, 4, 9, 10, 11, 12, 7, 6, 13, 14, 15, 16, 13, 4, 12, 17, 18, 19, 20, 21, 10, 8, 21, 22, 23, 24, 25, 26, 17, 4, 16, 27, 28, 29, 30, 31, 32, 27, 14, 11, 26, 33, 34, 35, 36, 37, 38, 39, 22, 4, 20, 39, 40, 41, 42, 43, 44, 45, 46, 33, 18, 15, 32, 47, 48, 49, 50, 51, 52, 53, 54, 47, 28, 4, 25, 46, 55, 56, 57, 58, 59, 60, 61, 62, 63, 40, 23, 19, 38
Offset: 1

Views

Author

Antti Karttunen, Jan 19 2020

Keywords

Comments

Restricted growth sequence transform of function: f(1) = -1, and for n>1, f(n) = A285722(n), when the latter is considered as an one-dimensional sequence.
For all i, j:
A331306(i) = A331306(j) => a(i) = a(j) => A072030(i) = A072030(j).

Crossrefs

Cf. also A331305, A331306.

Programs

  • PARI
    up_to = 25425; \\ = binomial(225+1,2)
    rgs_transform(invec) = { my(om = Map(), outvec = vector(length(invec)), u=1); for(i=1, length(invec), if(mapisdefined(om,invec[i]), my(pp = mapget(om, invec[i])); outvec[i] = outvec[pp] , mapput(om,invec[i],i); outvec[i] = u; u++ )); outvec; };
    A000027pairton(a,b) = ((2+((a+b)^2 - a) - (3*b))/2);
    A285722sq(n, k) = if(n==k,0,if(n>k,A000027pairton(n-k,k),A000027pairton(n,k-n)));
    A285722list(up_to) = { my(v = vector(up_to), i=0); for(a=1,oo, for(col=1,a, i++; if(i > up_to, return(v)); v[i] = A285722sq(col,(a-(col-1))))); (v); };
    v285722 = A285722list(up_to);
    A285722(n) = v285722[n];
    A331307aux(n) = if(1==n,-n,A285722(n));
    v331307 = rgs_transform(vector(up_to, n, A331307aux(n)));
    A331307(n) = v331307[n];
Showing 1-2 of 2 results.